CN113406252A - Method for simultaneously determining 10 quaternary ammonium salt bactericides in oral cleaning and nursing product - Google Patents
Method for simultaneously determining 10 quaternary ammonium salt bactericides in oral cleaning and nursing product Download PDFInfo
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- G—PHYSICS
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Abstract
The invention relates to a method for simultaneously measuring 10 quaternary ammonium salt bactericides in an oral cleaning and nursing product, which adopts a detection method combining a high performance liquid chromatograph and an evaporative light scattering detector, wherein the high performance liquid chromatograph adopts a surfactant column, and a mobile phase is a mixture of A: 50mmol/L aqueous ammonium acetate solution (pH 5.5) and B: mixed phase composed of acetonitrile. Therefore, the components of the quaternary ammonium salt bactericide in 10 parts in the oral cleaning and nursing products (toothpaste and mouthwash) can be separated, and the content of the quaternary ammonium salt bactericide can be quantified by an evaporative light scattering detector, so that the method is a quick and effective qualitative and quantitative determination method.
Description
Technical Field
The invention relates to the field of chemical product detection, in particular to the field of cosmetic detection, and more particularly relates to a method for simultaneously determining 10 quaternary ammonium salt bactericides in an oral cleaning and nursing product.
Background
The quaternary ammonium salt bactericide is a broad-spectrum bactericide of cationic surfactants, and has the characteristics of high-efficiency bactericidal ability, strong permeability, low toxicity and the like. In 1915, Jacobs W synthesizes quaternary ammonium salt compounds for the first time, and the compounds are found to have certain bactericidal capacity. The quaternary ammonium salt bactericide has good bactericidal action on yeast, fungi, gram-positive bacteria, gram-negative bacteria, trichomonas, protozoon and the like. Therefore, the quaternary ammonium salt compound is used as a bacteriostatic agent in oral cleaning and nursing products.
However, excessive use of quaternary ammonium salt bactericides can cause allergic conjunctivitis, vision loss, contact dermatitis, burn poisoning, and even death. Franklin found that the alkyl chain length of the quaternary ammonium salt of the same type is shorter than that of the alkyl chain, the alkyl chain length is the same, the toxicity of the quaternary ammonium salt with the methyl group is higher than that of the quaternary ammonium salt with the benzyl group, the toxicity of the quaternary ammonium salt with the methyl group is higher than that of the quaternary ammonium salt with the methyl group, and the toxicity of the quaternary ammonium salt with the methyl group is higher than that of the quaternary ammonium salt with the monoalkyl group, and the toxicity of the quaternary ammonium salt with the monoalkyl group is higher than that of the quaternary ammonium salt with the dialkyl group.
Therefore, quaternary ammonium salt bactericides contained in oral cleaning and care products such as toothpaste, mouthwash and the like must be supervised so as to ensure the safety of the products. Products such as toothpaste are managed according to the regulations on supervision and management of cosmetics, published by the national institute of health, day 16, 6/2020, in accordance with the regulations on general cosmetics. The total amount of dodecyldimethylbenzyl ammonium chloride, tetradecyldimethylbenzyl ammonium chloride, hexadecyldimethylbenzyl ammonium chloride and octadecyldimethylbenzyl ammonium chloride must not exceed 0.1% (calculated as benzalkonium chloride) according to the relevant technical specifications for cosmetic safety (2015 edition) and the european union cosmetic code (Council Directive 76/768/EEC), and dodecyltrimethyl ammonium chloride, tetradecyltrimethyl ammonium chloride, hexadecyltrimethyl ammonium chloride, octadecyltrimethyl ammonium chloride and docosyltrimethyl ammonium chloride must not be used in an amount greater than 0.25% for the stay-behind type products.
Therefore, how to quickly perform qualitative and quantitative analysis on the quaternary ammonium salt bactericide in the oral cleaning product mainly represented by toothpaste provides reliable data for safety supervision of related products, guarantees use safety of consumers, and becomes a research hotspot of technicians in the field.
Because the compounds to be detected have similar structures and properties, the compounds are difficult to separate; meanwhile, the toothpaste contains auxiliary materials such as a thickening agent and the like, so that the problems of difficult effective extraction, easy blockage and damage to a high-precision testing instrument in detection exist.
Therefore, effective pretreatment is carried out on samples such as toothpaste and the like, so that the damage to instruments in subsequent detection and analysis is avoided, and meanwhile, the effective separation of 10 quaternary ammonium salt bactericides in the product becomes a technical difficulty which needs to be overcome by technical personnel in the field.
Disclosure of Invention
The invention aims to solve the technical problem of developing a method for simultaneously measuring 10 quaternary ammonium salt bactericides in oral cleaning and nursing products, so that the content of dodecyl trimethyl ammonium chloride, dodecyl dimethyl benzyl ammonium chloride, benzethonium chloride, tetradecyl trimethyl ammonium chloride, tetradecyl dimethyl benzyl ammonium chloride, hexadecyl trimethyl ammonium chloride, hexadecyl dimethyl benzyl ammonium chloride, octadecyl trimethyl ammonium chloride, octadecyl dimethyl benzyl ammonium chloride and docosyl trimethyl ammonium chloride in the products can be accurately extracted and quickly measured.
In order to solve the technical problems, the invention discloses a method for simultaneously measuring quaternary ammonium salt bactericide in an oral cleaning and nursing product 10, which is a detection method combining a high performance liquid chromatograph and an evaporative light scattering detector, wherein the high performance liquid chromatograph adopts a surfactant column, a mobile phase is a mixed phase, and the ratio of A: 50mmol/L aqueous ammonium acetate solution (pH 5.5) and B: acetonitrile, adopting a gradient elution mode, wherein the gradient elution procedure is as follows: 0.0-5.0 min, 75-35% A, 5.0-15.0 min, 35-20% A, 15.0-20.0 min, 20% A, 20.0-21.0 min, 20-75% A, 21.0-25.0 min and 75% A, wherein the proportion of the mobile phase changes gradually at a constant speed;
that is, the composition ratio of the mobile phase at each time point of the mobile phase is as shown in table 1:
table 1:
and the changes shown in the table are all constant speed changes;
meanwhile, the detection conditions of the evaporative light scattering detector are as follows: the evaporation temperature is 40 ℃, the atomizer temperature is 40 ℃, the atomizing gas is nitrogen, and the carrier gas flow rate is as follows: 1.5 SLM.
Further preferably, the flow rate of the mobile phase is 1.0mL/min, and the analysis time is 25 min.
Further preferably, the sample amount is 10 μ L.
Further preferably, the column temperature of the chromatography column is 30 ℃.
In a preferred technical scheme, the pretreatment method of the toothpaste sample is further disclosed, and the pretreatment method specifically comprises the following steps of uniformly mixing the toothpaste sample to be detected with anhydrous sodium sulfate, adding methanol, carrying out ultrasonic extraction, centrifuging, and taking supernatant as a test sample.
According to the invention, through the pretreatment of the toothpaste sample, auxiliary materials such as thickening agents and the like harmful to the detector can be removed, and the extraction of the component to be detected of the quaternary ammonium salt bactericide in the toothpaste is not influenced, so that the expensive detector can be protected from being damaged, the extraction accuracy of the component to be detected can be ensured, and the content of the bactericide component in a reaction product is better.
Further preferably, the mixing ratio of the toothpaste sample to the anhydrous sodium sulfate is 1: 5.
Further preferably, the invention also discloses a preparation method of the test sample of the mouthwash, which comprises the following steps of dissolving the mouthwash sample to be tested in methanol, and uniformly mixing to obtain the test sample.
By adopting the technical scheme disclosed by the invention, the components of the quaternary ammonium salt bactericide in 10 parts in oral cleaning and nursing products (toothpaste and mouthwash) can be separated, and the content of the quaternary ammonium salt bactericide can be quantified by an evaporative light scattering detector, so that the method is a quick and effective qualitative and quantitative determination method. According to verification, the detection method disclosed by the invention has the advantages that within the addition level range of (50-500) mg/kg, the average recovery rates of dodecyl trimethyl ammonium chloride, dodecyl dimethyl benzyl ammonium chloride, benzethonium chloride, tetradecyl trimethyl ammonium chloride, tetradecyl dimethyl benzyl ammonium chloride, hexadecyl trimethyl ammonium chloride, hexadecyl dimethyl benzyl ammonium chloride and octadecyl trimethyl ammonium chloride in the toothpaste sample and the mouthwash sample are 87.9-103.1%, and the RSD values are less than 4.9%. Within the addition level range of (100-1000) mg/kg, the average recovery rate of octadecyl dimethyl benzyl ammonium chloride and docosyl trimethyl ammonium chloride in the toothpaste sample and the mouthwash sample is 90.3-96.4%, and the RSD value is less than 5.5%. The recovery rate and precision data of the detection method disclosed by the invention both accord with the technical index of residue analysis, and the method is accurate.
Drawings
FIG. 1 is a high performance liquid chromatogram of standard substance added with 10 quaternary ammonium salt bactericides.
Figure 2 is a chromatogram of a toothpaste sample.
FIG. 3 is a sample chromatogram of mouthwash.
Detailed Description
In order that the invention may be better understood, we now provide further explanation of the invention with reference to specific examples.
EXAMPLE 1 preparation of quantitative curves
Preparation of mixed standard working solution:
respectively and accurately weighing a certain amount of 10 quaternary ammonium salt bactericide standard substances, respectively dissolving the standard substances by using methanol and fixing the volume to 10mL to prepare single standard stock solutions with mass concentration of 10000mg/L, respectively transferring a certain volume of the single standard stock solutions to prepare mixed standard working solutions (the concentrations of dodecyl trimethyl ammonium chloride, dodecyl dimethyl benzyl ammonium chloride, benzethonium chloride, tetradecyl trimethyl ammonium chloride, tetradecyl dimethyl benzyl ammonium chloride, hexadecyl trimethyl ammonium chloride, hexadecyl dimethyl benzyl ammonium chloride and octadecyl trimethyl ammonium chloride are 200mg/L, and the concentrations of octadecyl dimethyl benzyl ammonium chloride and docosyl trimethyl ammonium chloride are 400 mg/L).
Diluting the mixed standard working solution step by step into a series of standard working solutions, and measuring according to the following instrument conditions:
a chromatographic column: acclaim surface (5 μm, 4.6 mm. times.150 mm, Thermo Co., USA); mobile phase: a-50mmol/L aqueous ammonium acetate (pH 5.5), B-acetonitrile, gradient elution procedure: 0.0-5.0 min, 75-35% A, 5.0-15.0 min, 35-20% A, 15.0-20.0 min, 20% A, 20.0-21.0 min, 20-75% A, 21.0-25.0 min, 75% A; temperature of the column: 30 ℃; the sample injection amount is 10 mu L; the flow rate of the mobile phase is 1.0 mL/min; the analysis time is 25 min; an evaporative light scattering detector, wherein the evaporation temperature is 40 ℃, the atomizer temperature is 40 ℃, the atomizing gas is nitrogen, and the carrier gas flow rate is as follows: 1.5 SLM.
The method comprises the steps of adopting an external standard method for quantification, taking the concentration of each analyte as an abscissa and the corresponding peak area as an ordinate, establishing a standard curve to obtain a linear regression equation of the quaternary ammonium salt bactericide, calculating the quantification Limit (LOQ) of an instrument by using a 10-time signal-to-noise ratio (S/N ═ 10), and obtaining results as shown in table 2 and fig. 1, wherein the numbers in fig. 1 correspond to the numbers in table 2 one by one.
Table 2: retention time and linear equation of 10 kinds of quaternary ammonium salt bactericide
Example 2 verification of recovery and precision
And respectively taking a negative toothpaste sample and a mouthwash sample as samples, and performing a recovery rate test and a precision test by adopting a standard adding method according to the test conditions, wherein three adding levels are performed, and each adding level is performed for 6 times in parallel.
Table 3 recovery on normalized scale and relative standard deviation of 10 quaternary biocides in negative samples (n ═ 6)
Through calculation, within the addition level range of (50-500) mg/kg, the average recovery rates of dodecyl trimethyl ammonium chloride, dodecyl dimethyl benzyl ammonium chloride, benzethonium chloride, tetradecyl trimethyl ammonium chloride, tetradecyl dimethyl benzyl ammonium chloride, hexadecyl trimethyl ammonium chloride, hexadecyl dimethyl benzyl ammonium chloride and octadecyl trimethyl ammonium chloride in the toothpaste sample and the mouthwash sample are 87.9-103.1%, and the RSD value is not more than 4.9%. Within the addition level range of (100-1000) mg/kg, the average recovery rate of octadecyl dimethyl benzyl ammonium chloride and docosyl trimethyl ammonium chloride in the toothpaste sample and the mouthwash sample is 90.3-96.4%, and the RSD value is not more than 5.5%.
EXAMPLE 3 detection of toothpaste samples
Sample pretreatment
Weighing 1.0g (accurate to 0.01g) of sample in a 50mL centrifuge tube, adding 5g of anhydrous sodium sulfate, stirring and mixing uniformly, adding 10mL of methanol, carrying out ultrasonic extraction at normal temperature for 5min, centrifuging for 3min by using a centrifuge, and filtering part of supernatant into a sample injection bottle by using an organic phase needle type filter head to serve as a sample.
Conditions of instrumental analysis
A chromatographic column: acclaim surface (5 μm, 4.6 mm. times.150 mm, Thermo Co., USA); mobile phase: a-50mmol/L aqueous ammonium acetate (pH 5.5), B-acetonitrile, gradient elution procedure: 0.0-5.0 min, 75-35% A, 5.0-15.0 min, 35-20% A, 15.0-20.0 min, 20% A, 20.0-21.0 min, 20-75% A, 21.0-25.0 min, 75% A; temperature of the column: 30 ℃; the sample injection amount is 10 mu L; the flow rate of the mobile phase is 1.0 mL/min; the analysis time is 25 min; an evaporative light scattering detector, wherein the evaporation temperature is 40 ℃, the atomizer temperature is 40 ℃, the atomizing gas is nitrogen, and the carrier gas flow rate is as follows: 1.5 SLM.
The detection result is shown in FIG. 2, and has a chromatographic peak at 9.850min, and the area thereof is statistically 579.9. By combining the standard data disclosed in Table 2, we can obtain the result that the sample to be tested contains octadecyl dimethyl benzyl ammonium chloride, and the content of octadecyl dimethyl benzyl ammonium chloride is 1511 mg/kg.
Example 4 detection of mouthwash samples
Sample pretreatment
Weighing 1.0g (accurate to 0.01g) of sample in a 10mL volumetric flask, using methanol to fix the volume to the scale, mixing uniformly, taking part of sample, filtering by an organic phase needle type filter head to a sample injection bottle to be used as a test sample.
Conditions of instrumental analysis
A chromatographic column: acclaim surface (5 μm, 4.6 mm. times.150 mm, Thermo Co., USA); mobile phase: a-50mmol/L aqueous ammonium acetate (pH 5.5), B-acetonitrile, gradient elution procedure: 0.0-5.0 min, 75-35% A, 5.0-15.0 min, 35-20% A, 15.0-20.0 min, 20% A, 20.0-21.0 min, 20-75% A, 21.0-25.0 min, 75% A; temperature of the column: 30 ℃; the sample injection amount is 10 mu L; the flow rate of the mobile phase is 1.0 mL/min; the analysis time is 25 min; an evaporative light scattering detector, wherein the evaporation temperature is 40 ℃, the atomizer temperature is 40 ℃, the atomizing gas is nitrogen, and the carrier gas flow rate is as follows: 1.5 SLM.
The result of the detection is shown in FIG. 3, which has a chromatographic peak at 8.498min, and the area thereof is statistically 262.8. By combining the standard data disclosed in Table 2, we can obtain the result that the sample to be tested contains hexadecyl dimethyl benzyl ammonium chloride and the content of the hexadecyl dimethyl benzyl ammonium chloride is 202 mg/kg.
What has been described above is a specific embodiment of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of the present invention, and such improvements and modifications are also considered to be within the scope of the present invention.
Claims (7)
1. A method for simultaneously measuring 10 quaternary ammonium salt bactericides in an oral cleaning and nursing product is characterized by comprising the following steps: the method is a detection method combining a high performance liquid chromatograph and an evaporative light scattering detector,
the high performance liquid chromatograph adopts a surfactant column, and the mobile phase is a mixed phase consisting of A: 50mmol/L aqueous ammonium acetate solution (pH 5.5) and B: acetonitrile, adopting a gradient elution mode, wherein the gradient elution procedure is as follows: 0.0-5.0 min, 75-35% A, 5.0-15.0 min, 35-20% A, 15.0-20.0 min, 20% A, 20.0-21.0 min, 20-75% A, 21.0-25.0 min and 75% A, wherein the proportion of the mobile phase changes gradually at a constant speed;
meanwhile, the detection conditions of the evaporative light scattering detector are as follows: the evaporation temperature is 40 ℃, the atomizer temperature is 40 ℃, the atomizing gas is nitrogen, and the carrier gas flow rate is as follows: 1.5 SLM.
2. The method of simultaneously determining a quat biocide in an oral cleaning care product 10 according to claim 1, wherein: the flow rate of the mobile phase was 1.0mL/min and the analysis time was 25 min.
3. The method of simultaneously determining a quat biocide in an oral cleaning care product 10 according to claim 1, wherein: the sample size was 10. mu.L.
4. The method of simultaneously determining a quat biocide in an oral cleaning care product 10 according to claim 1, wherein: the column temperature of the chromatographic column was 30 ℃.
5. The method of simultaneously determining a quat biocide in an oral cleaning care product 10 according to claim 1, wherein: the pretreatment method of the toothpaste sample comprises the following steps of uniformly mixing the toothpaste sample to be detected with anhydrous sodium sulfate, adding methanol, carrying out ultrasonic extraction, centrifuging, and taking supernatant as a test sample.
6. The method of simultaneously determining a quat biocide in an oral cleaning care product 10 according to claim 1, wherein: the mixing ratio of the toothpaste sample to the anhydrous sodium sulfate is 1: 5.
7. The method of simultaneously determining a quat biocide in an oral cleaning care product 10 according to claim 1, wherein: the preparation method of the test sample of the mouthwash comprises the following steps of dissolving a mouthwash sample to be tested in methanol, and uniformly mixing to obtain the test sample.
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